Stapler



Sept. 27, 1949.

G. D; WALKER ATTORNEY G. D. WALKER Sqn. 27, 1949.V

STAPLER 2 Sheets-Sheet 2 Filed May 26, 1947 INVENTOR. Gilbert D. Wq/kerATTO NEY Patented Sept. 27, 1.949

, UNITED STATES PATENT vOFFICE STAPLER l Gilbert D. Walker, Detroit,Mich.

ApplicationMay 26, 1947,l Serial No. 750,526

Claims.,

operated devices by means of which individual staples from a supplyl ina magazine portion off the device, may be driven into a chosen object.

Up to now the force necessary for the opera-v tion of such devices, wassolely m'anual, the mechanism therein being such that by exertion ofmanual effort, a coiled spring had first to be compressed toVsu'pply'driving power, whereupon the pent up energy of the spring wasreleased by meansV of a trigger mechanism, to impart to an individualstaple the penetrating thrust needed in stapling. Y Y

While on theA whole, devices of this kind have provedA fully practical,the operation of manually compressing the aforesaid spring, if continuedfor some time, was particularly tiresome and yexhausting to theoperators who after a prolonged period of using such a device wouldoften become incapacitated. In order, therefore, to eliminate thenecessity of manually compressing the above said spring, to supply thedriving power for individual staples, I have combined lwith a stapler ofthe conventional type, a mechanism of my-invention to convert what up tonow was purely a hand operated device, into a power tool actuated bycompressed air.

. As a result it became possible to operate the tool without undue`fatigue to the operators. Further, as a result of my improvement, itbecame possible to employ heavier springs and heavier staples withoutappreciably increasing the weight of the device or materially changingits shape. I wish to add that because of my im. provement the efficiencyof a stapler equipped therewith, has been greatly increased as the ,com`

pression of the staple-driving spring can now be effected very quickly.Y

YA further object of my invention was to provide all of the above namedadvantages without making my improved stapler too complicated instructure, or unduly expensive in cost.

I shall now describe my improvement in detail, including in mydescription the respective parts of the conventional device as workingin combination with the elementsv introduced by me. companying drawingsYin which:

, Fig. 1 is a perspective view ofa stapler as improved by me; j t

Fig. 2 is a vertical sectionalfview of my 'im-l proved stapler withparts shown inside eleva--Y tion; Y l

Fig. Sis aV vertical sectionalview of the stapler In my description, Ishall refer to the ac'- 2 with parts shown in side elevation, butdisclosing different operative positions of its elements;

Fig. 4 isa sectional view on line 4-4 of Fig. 2;

Fig. 5 is a sectional View on line 5-5 of Fig. 2;

Fig. 6 is a sectional View on line 6 6 of Fig. 2.

Similar numerals refer to similar parts throughout the several views.

The stapler includes a flat sheet metal case I0 open inits mid-sectionas shown at IIA to afford a space for a linger grip in operating saidstapler while the palm of the hand of the operator rests on hand leverI2 to which I shall presently refer. The front part of the case isexpanded laterally and forms a substantially rectangular cage I3extending upwardly above the rest of the body of said case. At its upperend the cage is closed by a flat topped cap I4, split on the side facingthe lever and being provided with a central circular aperture 22 in itstop. Equipped with ears I5 along the edges of the split, the cap may beclamped in place by means of a bolt I1.

Slidingly disposed within the cage I3 is a plunger including an oblongshell I8, substantially square in cross section, the shell being open attop, but provided with a flat bottom plate I9. Contained within theshell, and forming a part of the plunger assembly, is a coiled spring2B, bearingV at its lower 'end against said plate I9, and confined atits upper end under a cross pin 2|. The outer ends of the pin passthrough vertical slots 65 in the walls of th'e shell, and enter intovertical s1ots`4l in that portion of the well of the cage which iscovered by a hood or cap I4. Mounted upon the iiat top surface of thecap, axially with respect to the coiled spring 20, isa

Yshort cylinder 23 fitting over a disk-like base '24, having a marginalflange 25 for the support of the wall of thecylinder.

A plurality of spaced screws 26 passing through the Wall of the cylinderalong its lower fringe, into the body of the disk, radially, serve tokeep the cylinder in place` upon said base. Disposed within the cylinderis a piston including a head 21 and a supporting rod 28 which passesdownwardly through a centrally located'bearing 29 in said base 24. Aspring 62 coiled around the rod, bears against the head of the pistonfrom below, urging it upwardly.

An integrally formed elongated member 30, disposed externally of saidcylinder in parallel relation thereto, terminates at its upper end Yina'nipple 3| for attachment of a exiblehose 32 which is held in place bymeans of a clamp El. An internal Yduct 33 opening at its upperend intosaid hose, is 'controlled by a movable two faced valve 34 located andseated within a cham..

ber 35. A lateral passage 36 opens into the interior of the cylinder 23at a level above that of the head of the piston. Directly below valve 34is a downwardly extending cylindrical hole 31 axially alined with duct33. Slidingly tting into the upper end of the hole is a short movableprop 38 loosely supporting valve 34 from below. The prop itself rests ona lifter 39 which is connected to hand-lever I2. Specically the lift ismade of a length of wire which at its lower end is looped over a crossrivet 40. A leaf spring 42 at one end bearing against the upper surfaceof the body of case Ill, normally holds the lever fulcrumed within theside walls of case Ill at 43, in its uppermost position. With the leverin said position, the lifter, by means of the prop, wedges said valve 34into the mouth of duct 33 as shown in Fig. 2. The valve, it will be`noted, has the form of two frust-cones extending in opposite directionfrom their common base, one of the cones acting as a closure for duct33, while `the opposite cone, the lower one as shown in the drawings, isadapted to act as a `closure for hole 31 Where the latter opens intochamber 35. Leading outwardly from hole 31, below said chamber 35, isavent or port 60.

I shall now return to the details of construction having a bearing onthe compression v,of spring 20. kIt will be noted that cross pin 2l isjournalled in a pair oi oblong arms 44 extending downwardly along theopposite walls of cage I3 and pivotally connected to a lever 46. Thelatter is made of two oblong metal strips joined Vin parallel abutmentalong a part of their length lto form a shank which is pivoted withinthe rear part of the case upon a bolt 41. The .strips are spread apartin a fork formation at their opposite ends where they are connected tothe lower ends of arms 44 as above indicated. A'spring 48 exerts apressure against the lever upwardly. A roller 49 mounted within theforked portion of the lever is adapted to bear against arm 50 of a pawlI pivoted on a bolt 52. The pawl is in.- dented at 53 so as to normallyrit under the edge of plate I9 of the shell IB enclosing coiled spring23. A spring 54, anchored within the casing keeps the pawl normally inposition shown in Fig. 2 wherein the respective part of the pawl jutsout into the Vpath of shell I8 to prevent it from moving downwardly. Anintegrally formed tongue 55 extends from the opposite edge of the plateI3 and projects into a slot 55 in a staple driver 51.

The construction of the driver is similar in all Staplers, and so is itsaction upon the individual staples, so that further details with respectthereto do not seem to be necessary. However,

to conclude this part of the specication on the structure of thestapler, I want tov add the staples marked 58 are contained in amagazine section of the stapler in the base or shoe portion 59 of caseIIB. It may be also mentioned that the staples come in the form of aclip comprising a plurality of individual staples adhering to each otherand that by means of a spring arrangement they are fed, one by'one tothe ,delivery port through which they are thrust out by said driver. Astop limiting the `operative downwardmovement of the plunger is marked63 and includes a resilient shock absorber or :cushion 64.

After having described the structure of the stapler, I shall nowdescribe the operation thereof:

It will be assumed that hose 32 `is .connected to a source of.compressed airand that'such air is available for use in said stapler. Asmay al ready be obvious from the description of the respective parts ofthe device, the admission of air to operate the same, is controlled bymeans of valve 34. Normally, as shown in Figure 2, the valve blocks theduct 33 being held in the mouth thereof by means of prop or valve guide38 resting on top of lifter 39. On depressing lever I2, manually, lifter39, which at its lower end is connected to the lever, will be pulleddownwardly allowing the valve to be pushed by air pressure out of themouth of the duct and against the mouth of hole 31 in the bottom ofchamber 35. Air entering said chamber from duct 33, will rush intocylinder 23 through a lateral passage 36, and overcoming the tension ofspring 6l, under the piston head 21, will push the piston downwardlycausing its rod 28 to bear against said cross pin 2| and to compressspring 2Q. Simultaneously, arms or links 44 journalled upon the pin willdepress lever 46 lowering roller 49 to bear against arm 50 of pawl 5I.By the time said roller beg-ins to bear against said arm, spring 2D will`have been sufciently -compressed within shell I8 of the plunger to havethe desired amount of power needed for the stapling. Swung on itspivotal support `by the pressure of the roller, the pawl will slip outfrom under the bottom plate Ie Aof shell I3, thereby releasing the com.-pressed spring therein to thrust the shell down,u wardly against theshock absorbing cushion ,64 of sto-p 63. The bottom plate of the shellbeing interlocked with the driver by means .of tongue 55 will slam saiddriver against the `solid end of Y the respective staple 58, forcing it.outwardly to a position shown in dotted line 58a.

On release of lever I2, leaf spring 42 will cause said lever to returnto its initial position shown in Fig. 2l causing valve 34 by means oflifter 39 to close the mouth of duct 33 to cut olf supply of air underpressure. Coiled spring .62 within cylinder 23, will now move the pistontherein upwardly to its initial position forcing `out the air above thepiston through passage 35 into chamber 35 and thence downwardly intovent 60 and outwardly therefrom. This is possible because oi theposition of valve 34, which by means of the lifter has been returned tovits noru mal position .blocking duct 33 but leaving the Way to the ventopen. With the recession of the piston including its rod 28, upwardlyspring 48 within case Ill will cause lever 45 to swing up transmittingthe movement to arms or links 44 and b y means thereof Lto shell I8 tillsaid shell with spring 23 therein, has resumed its original position asshown in Fig. 2.

It will be obvious that some changes may be made inthe structuraldetails of the stapler as improved by me, without departing from theinventive vprinciple disclosed herein. What I, therefore, wish to claim,is as follows:

`1. A staple driver comprising a casing, said casing having acompartment for receiving a plurality of staples, a staple driver, aspring for actuating said driver, pneumatically actuated means tocompress the spring, trigger means to support the spring while it isbeing compressed, link and lever mechanism operatively associated withsaid spring and located in the path of said trigger to trip the triggerwhen the spring has been compressed to cause said spring to thrust the`driver against thestaple to vloe driven, in combination with Valvemeans Vto control said pneumatically actuated means, and means pivotedto said casing to. 4control the valve.

2. In a stapler of the kind described, comprising a casing having a basefor supporting a plurality of staples, a slidable driver for driving thestaples, an oblong shell above the driver and receiving a coiled spring,a plate on the bottom of said shell connected to the driver andconstituting a support for the spring, a cylinder mounted upon thecasing above the shell, a piston therein having a piston rod extendingoutwardly against a pin disposed transversely in the shell over theupper end of said spring, air conducting means to supply air underpressure to the cylinder to move the piston in the direction of thespring to compress said spring against said plate, a trigger under theplate to support the driver while said spring is being compressed,valveV means within the air conducting means to control the supply ofair under pressure to the cylinder, hand-lever means onrthe casing tooperate the valve, link and lever mechanism responsive to the movementof the piston towards the spring to trip said trigger to cause saidspring to thrust the driver into driving action againstV the staple tobe driven, spring means within the cylinder to return the piston and itsrod to its original position on cutting off the supply of air underpressure, and a torsion spring within the casing operatively connectedwith the link and lever mechanism to return the support for the coiledspring with the driver to their initial positions.

3. In a stapler of the kind described comprising a casing having a basecompartment for receiving staples, a at driver located above the basecompartment in the plane of one end thereof, an oblong hollow shellwithin the casing, said shell having a bottom plate interlocked with theupper end of the driver, a coiled compression spring within the shelland bearing at its inner end against said bottom plate, a cylindermounted on the casing above the shell and axially aligned therewith, apiston within the cylinder said piston including a piston rod extendinginto the shell and bearing against a cross pin disposed over the upperend of the spring, air conducting means to convey compressed air intothe cylinder to move the piston in the direction of the spring and tocompress said spring, a valve in said air conducting means, a hand leverpivoted to the casing to control the valve, trigger means under the edgeof the bottom plate of the shell to hold the shell stationary while thespring is being compressed, link and lever mechanism connected to saidcross pin to trip said trigger upon compression of the spring to providefor the downward thrust of the shell, spring means within the cylinderto return the piston and its rod to its initial position upon closing ofthe valve, and a torsion spring within the casing operatively connectedwith the link and lever mechanism Yto return the support for the coiledspring with the driver to their initial positions.

4. In a stapler comprising a casing, said casing having a compartmenttherein located in the base thereof and adapted to receive a pluralityof aligned staples, a driver, an oblong shell within the casing abovethe driver. a coiled compression spring within the shell, the spring atits lower end bearing against the bottom end of the shell, said bottomend having a lateral projection thereon connecting the shell with thedriver, a cylinder mounted upon the casing in axial relation to saidshell, a piston movable within the cylinder, a piston rod extendingtherefrom toward the spring and into the shell, a cross pin interposed`between the upper end of the spring and the outer end of the pistonrod, said piston rod normally bearing against said cross pin, airconducting means adjoining the cylinder to convey thereto air underpressure from an outside source to cause the spring within the shell tobe compressed by the action of the piston, valve means in said airconducting means to control admission of air into the cylinder, acombined hand lever and rod means to control the valve, trigger meansunder the shell to hold the shell while the spring is being compressed,a lever actuated through intermediate means by the piston to trip thetrigger upon compression of the spring to cause the shell, spring andpiston to thrust the driver across the front end of the compartment,spring means to return the piston and itsrod back to their initialpositions upon closing of said valve, and a torsion spring connected tothe lever to return the lever, intermediate means and shell with thedriver, and actuating spring to their original positions upon retractionof the piston rod.

5. In a stapler comprising a casing having a hollow shoe portionprovided with a iiat surface for receiving aligned staples, a shellslidably disposed within the casing at right angles to said iiatsurface, the shell having a transverse bottom plate, a driver disposedabove the hollow shoe portion within and along the lower front margin ofthe casing, a coiled spring Within the shell and bearing at one endagainst said bottom plate, a tongue projecting laterally from said plateinto a slot within the driver to secure the same thereto, a cylindermounted on top of said casing having its axis at right angles to thesurface of the shoe and co-axially with the shell, a piston within thecylinder, the piston including a piston rod extending into the shell andbearing on a cross pin ydisposed transversely of and against the otherend of the spring within the shell, means on the cylinder comprising avalve controlled inlet and outlet construction in communication withsaid cylinder connected to and in communication with a source ofcompressed air, hand lever and rod means to control said valve for theadmission of air to the cylinder, a pivoted support under the edge ofthe shell, link and lever mechanism connected to the cross pin towithdraw said pivoted support from under the shell upon compression ofthe spring by the piston thereby releasing the shell to thrust thedriver against the staple to be driven, spring means to return thepiston and its rod to their initial positions, and a torsion springwithin the casing operatively connected with the link and levermechanism to return the shell, its spring and the driver to theirinitial positions.

GILBERT D; WALKER.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Number

